It's because this bakery is run by Kogawa Keikaku, who runs a driving school in Shimane Prefecture, M land Masuda branch. All staff members belong to that driving school and some of them used to go to that school to get a driver's license.

自動車学校のHPに「そしてＭランドといえば笑顔と挨拶」と書いてある通り、笑顔がほんとに素敵なスタッフさん達です。

As this quote promises "And when it comes to M land, you won't miss to see our smile and greetings," they have such nice smiles.